1. Field of the Invention.
This invention pertains to seating, and more particularly to chairs having tiltable seats and backrests.
2. Descriction of the Prior Art.
A large variety of chair designs have been developed over the years in attempts to provide comfort to their occupants. Chairs having tilting backrests and seats are especially comfortable, and they are in widespread use.
In some tiltable chairs, parallelogram linkages of various types are employed by which the chair seat rises in correlation with reclining of the backrest. An exemplary chair in which the seat rises and moves backwardly toward the backrest as the backrest reclines is disclosed in my co-pending U.S. Pat. Application Ser. No. 050,862, filed May 18, 1987. A major advantage of the chair of U.S. Patent Application Serial No. 050,862 is that the backrest and seat tilting mechanism occupies very little space, making it suitable for installation in stackable chairs.
In some chairs of somewhat simpler design, the seat tilts about a fixed point on the chair frame. For example, many chairs are constructed such that a reclining backrest causes a simultaneous pivoting of the seat about a pivot point located under the seat front edge. In some of those designs a reclining of the backrest causes the seat back edge to rotate upwardly about the front pivot point, i.e., the seat back end rises with backrest reclining. An example of such construction may be seen in French Patent No. 2,045,120. In the chair of the French patent, a pin and slot arrangement pivotally join the backrest to the seat to enable tilting of those components relative to the chair frame and to each other. The seat and backrest are pivotable in two directions about respective central positions. A major disadvantage of the tilting mechanism of the French chair is the frictional connection between the backrest and the seat. Further, the tilt mechanism requires a great deal of space, thereby precluding the chair from being stackable.
Thus, presently available tilting chairs are subject to further improvement and development.